Extracting trail and road data from OpenStreetMap

Create a bounding box for the study area

glac_bbox <- 
  # approximate bounding box for Glacier National Park
  sf::st_bbox(c(xmin = -114.47552, ymin = 48.23369, xmax = -113.24198, ymax = 49.0000))

Get trail data

Note: this includes the classifications of ‘path’ (multi-use), ‘footway’ (foot traffic only), and “steps” (i.e. stairs)

trails <- 
  osmdata::opq(bbox = glac_bbox) %>% 
  osmdata::add_osm_feature(key = 'highway', value = c("path", "footway", "steps")) %>% 
  osmdata::osmdata_sf()

Get trailhead data

Note: this is specifically for named trailheads. There are numerous parking areas that are at the start of trails that do now show up as trailheads.

trailhead <- 
  osmdata::opq(bbox = glac_bbox) %>% 
  osmdata::add_osm_feature(key = 'highway', value = c("trailhead")) %>% 
  osmdata::osmdata_sf()

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Get parking area data

This seems like it could be useful to augment trailhead data. That said, parking areas include many pull outs along roads that are deffinitly not trail access locations.

# parking <-
#   osmdata::opq(bbox = glac_bbox) %>%
#   osmdata::add_osm_feature(key = 'amenity', value = c("parking")) %>%
#   osmdata::osmdata_sf()

Get data for all road types

Note the number of different road classifications that OpenStreetMap uses. All common road types are included below.

all_roads <-
    osmdata::opq(bbox = glac_bbox) %>%
    osmdata::add_osm_feature(
      key = 'highway', 
      value = c("motorway", "trunk", "primary", "secondary", "tertiary", 
                "unclassified", "residential", "motorway_link", "trunk_link", 
                "primary_link", "secondary_link", "tertiary_link", 
                "living_street", "service")
    ) %>%
    osmdata::osmdata_sf()